Transform attributes in request body

Question

I have used @Transform decorator from class-transformer to sanitize specific fields in user input.

import { IsString } from "class-validator";
import { Transform } from "class-transformer";

export class SearchRequestDto {
  @Transform((data) => data.value && sanitizeRegex(data.value))
  @IsString()
  readonly term: string = '';
}

How can I create a new decorator to add this transformer to DTO more straight forward. Like this:

export class SearchRequestDto {
  @Regex()
  @IsString()
  readonly term: string = '';
}

Answer 1

You can create a Custom Decorator that looks like this:

export const Regex = () => Transform((data) => data.value && sanitizeRegex(data.value))

And then use it the way you wanted:

export class SearchRequestDto {
  @Regex()
  @IsString()
  readonly term: string = '';
}